How to add only new markers to the map?

Question

iOS

The bottom line is that when I change the coordinates of the map (they moved the scale, changed), there is a request to the server for selecting markers .. how not to update everything but add only those that are not currently on the google maps map?

Answer 1

СЕРВЕР ДАЙ мне МАРКЕРЫ КРОМЕ(1, 4, 7, 90)